They are crumbly, but I wonder if maybe your butter got too warm, or if your flour measurements were off a bit on the low side? I know she said for the butter to be room temperature, but I would try chilling it and possibly add a bit more flour. You could also try refrigerating them before baking them--that should help them hold together better. It's sad because they're really wonderful--I hope this helps. (And maybe TheRunawaySpoon will see this and weigh in).